JP2002083533A - Electric leakage detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric leakage detecting device capable of preventing burnout of a coil or a thyristor of an electromagnet device caused by continuous current supply even in the case where an electric leakage test switch is continuously pressed in a state that an electric leakage display button is bound or in the case where the earth occurs. SOLUTION: This electric leakage detecting device comprises a release type electromagnet device 7 formed so that a moving iron core 12 is excited by the detection of earth current to project; and the electric leakage display button 28 projecting together with the projection of the moving iron core 12 displaying the generation of electric leakage, and moreover equipped with a burnout preventing switch 35 comprising a switch cutting off an exciting circuit of the release type electromagnet device 7 by the projection of the moving iron core 12 and a switch cutting off the exciting circuit of the release type electromagnet device 7 by the projection of the electric leakage display button 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an earth leakage circuit breaker and an earth leakage relay, and more particularly to an earth leakage detection device provided with an earth leakage display button for indicating that earth leakage has occurred when a ground fault occurs.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, JP-A-8-180792.
FIG. 1 is an electric circuit diagram showing a conventional earth leakage breaker similar to that shown in Japanese Unexamined Patent Application Publication No. H10-86,004. In the figure, 1 is a power supply terminal for connecting a power supply, 2 is a load terminal for connecting a load, and 3 is a power supply terminal 1.
4 is a zero-phase current transformer for detecting a ground fault current flowing in the circuit 3; 5 is an amplifier for amplifying the secondary output of the zero-phase current transformer 4 to determine its level; Reference numeral 6 denotes a thyristor that switches based on a determination signal from the amplifier 5, reference numeral 7 denotes a release type electromagnet device controlled by the thyristor 6,
Is a ground fault display button for displaying that a ground fault has occurred in the electric circuit 3,
Reference numeral 9 denotes a burnout prevention switch for preventing the coil of the electromagnet device 7 from being burned out. Reference numeral 10 denotes a leakage test switch, which artificially causes a pseudo-parallel current to flow to the zero-phase current transformer 4 by pressing a test button. . Reference numeral 11 denotes a test resistor for suppressing and adjusting a pseudo non-parallel current flowing in the leakage test.

FIG. 8 is a configuration diagram showing a main part of a conventional leakage detection device. In the figure, 12 is a release type electromagnet device 7
A movable iron core 13 of the electromagnet device 7 (hereinafter referred to as an electromagnet device 7) is an iron core spring, and a current flows through the electromagnet device 7 to excite the coil 7a, and acts between the movable iron core 12 and a permanent magnet (not shown). When the attraction force is canceled, the movable iron core 12 is urged so as to release the movable iron core 12 in the direction of the arrow A to protrude. 14 is a latch engaged with the engaging portion 8a of the leakage display button 8, 15 is a latch spring for urging the latch 14 in the direction of arrow E so as to return, and 16 is a projection of the leakage display button 8 in the direction of arrow B. This is a button spring that urges the user to make the button spring.
Reference numeral 17 denotes a test-off plate that contacts or separates in response to the operation of the leakage display button 8, reference numeral 18 denotes a substrate on which the test-off plate 17 is provided, and reference numeral 19 denotes a test-off plate provided to face the test-off plate 17. It is a fixed contact. The test-off plate 17
The substrate 9 and the test-off fixed contact 19 constitute the burnout prevention switch 9.

[0004] The conventional earth leakage detecting device is configured as described above. For example, when a ground fault occurs, the zero-phase current transformer 4 detects the ground fault current, and the detection signal is detected and amplified by the amplifier 5 and is amplified by the thyristor 6. Is turned on, and the coil 7a of the electromagnet device 7 is turned on.
Is excited. Since the attractive force acting between the movable core 12 and the permanent magnet (not shown) is canceled by this excitation, the movable core 12 is released by the urging force of the iron core spring 13 and protrudes to move the latch 14 in the direction of arrow A. Push. This push causes the latch 14 to rotate in the direction of arrow F, disengage the latch engaging portion 14a from the button engaging portion 8a, and release the button spring 16
Causes the electric leakage display button 8 to protrude in the direction of arrow B to indicate that electric leakage has occurred. Along with this display, the button arm 8c
As a result, the movable iron core 12 is pushed up in the direction of arrow C to return to the original state. At this time, the test-off plate 17 pressed by the pressing portion 8b of the leakage display button 8 is separated from the test-off fixed contact 19, and the burnout prevention switch 9 is turned off.
Even if the ground fault continues, current does not flow through the coil 7a of the electromagnet device 7, thereby preventing the coil 7a of the electromagnet device 7 and the thyristor 6 from burning.

When the leakage test switch 10 is turned on for the leakage test, a current flows through the test circuit through the test resistor 11, which is detected and amplified by the amplifier 5, and the thyristor 6 is turned on. Similarly, the burnout prevention switch 9 is turned off. Therefore, even when the electric leakage test switch 10 is kept pressed, current does not flow through the coil 7a of the electromagnet device 7, thereby preventing the coil 7a of the electromagnet device 7 and the thyristor 6 from burning.

[0006]

In the above-described conventional earth leakage detecting device, the burnout prevention switch 9 is connected to the test-off plate 1.
7 is configured to be turned on / off by the operation of the pressing portion 8b of the leakage display button 8, so that the leakage display button 8
When a ground fault is generated in a state where it is pressed in the direction indicated by arrow B and is prevented from projecting in the direction of arrow B, or when a leakage test is performed, the test-off plate 17 is pressed by the pressing portion 8 of the leakage display button 8.
b and is not released from the test-off fixed contact 19. That is, since the burnout prevention switch 9 remains in the ON state and a current continuously flows through the electromagnet device 7, there is a problem that electric components such as the coil 7a and the thyristor 6 of the electromagnet device 7 are burnt.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. Even if the leakage display button is restrained from being projected by an external force, the burnout prevention switch is turned off. It is an object of the present invention to provide a leakage detecting device that can turn off a current flowing through a coil of an electromagnet device and prevent burnout of electric components such as a coil and a thyristor of the electromagnet device.

[0008]

According to the present invention, a zero-phase current transformer for detecting a ground fault current in an electric circuit, and a movable core is controlled to protrude by a secondary output of the zero-phase current transformer. A release type electromagnet device, and a leakage detection device including a leakage display button for projecting in conjunction with the protrusion of the movable core and displaying that a leakage has occurred. There is provided a burnout prevention switch having a switch configured to cut off an excitation circuit and a switch operated by projecting a leakage indication button to cut off an excitation circuit of a release type electromagnet device. That is, even when the electric leakage display button is restrained, the excitation circuit of the release type electromagnet device is cut off by the protrusion of the movable iron core, thereby preventing the release type electromagnet device from burning.

In the burnout prevention switch, one of the contacts that come into contact with each other is activated by the protrusion of the movable iron core and is separated from the other contact, and the other contact is activated by the protrusion of the leakage display button. The switch is configured to be separated from one contact to simplify the configuration of the switch.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an electric circuit diagram showing an earth leakage breaker according to Embodiment 1 of the present invention.
FIG. 2 is a configuration diagram of a main part of the electric leakage detection device according to the first embodiment of the present invention, showing a state where electric leakage has not occurred, (A) is a front view, and (B) is a side view. . FIG.
It is a block diagram which shows the state in which the leakage occurred and the leakage detection apparatus displayed the leakage, (A) is a front view, (B) is a side view.
4A and 4B are configuration diagrams showing a state in which a leakage has occurred with the leakage display button of the leakage detection device restrained, wherein FIG. 4A is a front view and FIG. 4B is a side view. FIGS. 5A and 5B are diagrams showing a leakage display button, wherein FIG. 5A is a front view and FIG. 5B is a side view.
FIG. 6 is a diagram showing a fixed contact plate, (A) is a front view,
(B) is a side view.

1 to 4, reference numeral 1 denotes a power supply terminal, 2 denotes a load terminal, 3 denotes an electric circuit, 4 denotes a zero-phase current transformer, 5 denotes an amplifier, 6
Is a thyristor, 7 is a release type electromagnet device, 10 is a leakage test switch, and 11 is a test resistor. These are the same as the conventional device, and the description thereof is omitted.

In FIG. 1, reference numeral 35 denotes a release type electromagnet device 7.
A burnout prevention switch for preventing burnout of a coil of the electromagnetic device (hereinafter referred to as an electromagnet device 7), and an auxiliary switch 36, the structure and operation of which will be described later. Reference numeral 28 denotes a leakage display button, which is formed of a synthetic resin as shown in FIG.
8a, a button engaging portion 28b that engages with the latch 14, an arm portion 28c, and an insertion groove 28d into which a fixed contact plate 30 described later is inserted. Reference numeral 30 denotes a fixed contact plate, which is substantially U-shaped by using an elastic conductive plate as shown in FIG.
It has a fixed contact portion 30a which is formed in a symmetrical shape in the shape of a letter, and has a pair of contact pieces 30b which are formed to have elasticity and are curved. The fixed contact plate 30 has one of the contact pieces 30b inserted into an insertion groove 28d formed in the leakage button 28 by utilizing the elasticity of the contact piece 30b.

In FIG. 2, a fixed terminal 31 has a terminal piece 31a formed at one end thereof so as to be in contact with and separate from the contact piece 30b of the fixed contact plate 30, and the other end has a lead wire 31b.
Is electrically connected to the electromagnet device 7 via the. 32
Is a movable contact plate, which has a movable contact portion 32a provided at one end thereof so as to face the fixed contact portion 30a of the fixed contact plate 30, and the other end provided with an amplifier 5 (FIG. 1) via a thyristor 6 by a lead wire 32b. Shown)). The fixed contact plate 30 and the movable contact plate 32 constitute a burnout prevention switch 35. In addition, the fixed contact plate 30
The auxiliary switch 36 is composed of the fixed terminal 31 and the fixed switch 31.

In the earth leakage detecting device configured as described above, when a ground fault occurs in the electric circuit 3 or when the earth leakage test switch 10 (shown in FIG. 1) is pressed to be turned on,
A current flows through the coil 7a of the electromagnet device 7 to be excited. By this excitation, the attractive force acting between the movable iron core 12 and the permanent magnet (not shown) is canceled, so that the movable iron core 12 is released by the urging force of the iron core spring 13 and protrudes, as shown in FIG. Push the latch 14 in the direction of arrow A. By the movement of the latch 14, the latch engagement portion 14a and the button engagement portion 2
8b is disengaged, and the leakage display button 28 is projected from the upper surface of the housing 40 in the direction of arrow B by the urging force of the button spring 16 to display leakage as shown in FIG.

At the same time, since the spring load of the button spring 16 is set stronger than the spring load of the iron core spring 13, the movable iron core 12 is pushed up in the direction of arrow C by the arm portion 28c of the earth leakage display button 28. , Return to the same position as in FIG. At this time, since the fixed contact plate 30 is inserted into the insertion groove 28d of the leakage display button 28, the fixed contact plate 30 is pushed up in the direction of arrow C integrally with the leakage display button 28, and the fixed contact portion of the fixed contact plate 30 The movable contact portion 32a of the movable contact plate 32 is separated from the movable contact portion 30a. Therefore, even if the ground fault continues or the earth leakage test switch 10 is kept pressed, no current flows through the coil 7a of the electromagnet device 7 and the burnout of the coil 7a and the thyristor 6 of the electromagnet device 7 is prevented. can do.

Further, as shown in FIG.
8 is pushed in the direction of arrow D by external force and is constrained, and a ground fault occurs,
Is pressed and turned on, the coil 7 of the electromagnet device 7 is turned on.
is excited, and the movable iron core 12 is released by the urging force of the iron core spring 13 and protrudes. The protrusion of the movable core 12 pushes the latch 14 in the direction of arrow A. At this time, the movable contact plate 32 is pushed in the direction of arrow A via the latch 14 irrespective of the leakage display button 28. By this pushing, the fixed contact portion 30a of the fixed contact plate 30 and the movable contact plate 3
The two movable contact portions 32a are separated. Therefore, even if the ground fault continues to occur or the earth leakage test switch 10 is kept pressed, the coil 7a
No current flows through the coil, so that the coil 7a of the electromagnet device 7 and the thyristor 6 can be prevented from burning.

Next, a case in which the external force restricting the electric leakage display button 28 as described above is removed will be described. That is, in the state where the electric leakage display button 28 is pushed and restrained, the movable iron core 12 keeps pushing the latch 14 by the urging force of the iron core spring 13. If the external force is removed in this state, the leakage display button 28 and the latch 14 are disengaged, so that the leakage display button 28 projects from the surface of the housing 40 by the urging force of the button spring 16 to display the leakage. . Since the movable core 12 is reset to the original state by this protrusion, the movable contact plate 32 pressed via the latch 14 also returns to the original state. However, since the fixed contact portion 30a of the fixed contact plate 30 and the movable contact portion 32a of the movable contact plate 32 are separated by the projection of the leakage display button 28, if the ground fault continues to occur, or the leakage test switch 10 is kept pressed. Even when the current is applied, no current flows through the coil 7a of the electromagnet device 7.
Therefore, burning of the coil 7a of the electromagnet device 7 and the thyristor 6 can be prevented.

Embodiment 2 FIG. The burnout prevention switch 35 in the first embodiment is configured such that one of the contacts that come into contact with each other, that is, the movable contact portion 32a of the movable contact plate 32 is activated by the protrusion of the movable core 12, and the other contact, that is,
The fixed contact portion 30a of the fixed contact plate 30 is separated from the fixed contact portion 30a, and the fixed contact portion 30a of the fixed contact plate 30 is actuated by the projection of the leakage indication button, and one of the contacts, that is, the movable contact portion of the movable contact plate 32 Although the switch configured to be separated from 32a is shown, the burnout prevention switch 35 may be configured by two sets of switches. That is, a switch that is opened by the protrusion of the movable core 12 and a switch that is opened by the protrusion of the earth leakage display button 28 (for example, the burnout prevention switch 9 shown in the related art) may be connected in series. In the first embodiment, the auxiliary switch 36 also functions as a burnout prevention switch. However, depending on the configuration of the burnout prevention switch 35, the auxiliary switch 36 may not be provided.

[0019]

Since the present invention is configured as described above, even when the leakage display button is restrained, the current flowing through the coil of the electromagnet device is reliably turned off, and the coil, thyristor, etc. of the electromagnet device are turned off. Of the electric parts can be prevented.

In the burnout prevention switch, one of the contacts coming into contact with each other is activated by the protrusion of the movable iron core to be separated from the other contact, and the other contact is activated by the protrusion of the leakage display button. Since the switch is separated from the one contact, the structure of the burnout prevention switch is simplified, and the effect of reducing the size of the leakage detection device is exhibited.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a leakage detection device according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram illustrating a main part of the electric leakage detection device according to the first embodiment of the present invention, showing a state in which electric leakage has not occurred.

FIG. 3 is a configuration diagram illustrating a main part of a leakage detection device according to Embodiment 1 of the present invention, showing a state in which a leakage has occurred and a leakage is displayed.

FIG. 4 is a configuration diagram illustrating a main part of the leakage detection device according to the first embodiment of the present invention, illustrating a state in which a ground fault occurs with the leakage display button restrained.

FIG. 5 is a two-sided view showing an earth leakage display button according to Embodiment 1 of the present invention.

FIG. 6 is a two-sided view showing the fixed contact plate according to the first embodiment of the present invention.

FIG. 7 is an electric circuit diagram of a conventional leakage detection device.

FIG. 8 is a configuration diagram illustrating a main part of a conventional leakage detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 Electric circuit, 4 zero-phase current transformer, 5 amplifier, 6 thyristor, 7 release type electromagnet device, 12 movable iron core, 28 earth leakage display button, 30 fixed contact plate, 31 fixed terminal, 32
Movable contact plate, 35 Burnout prevention switch.

Claims (2)

[Claims] 1. A zero-phase current transformer for detecting a ground fault current in an electric circuit, a release-type electromagnet device in which a movable core is projected and controlled by a secondary output of the zero-phase current transformer, A leakage detection device including a leakage display button for projecting in conjunction with a leakage display button for displaying that a leakage has occurred, wherein a switch that is activated by the protrusion of the movable core to cut off an excitation circuit of the release type electromagnet device; An electric leakage detection device, comprising: a burnout prevention switch having a switch that is operated by projecting the electric leakage display button to cut off an excitation circuit of the release type electromagnet device. 2. The burnout prevention switch is configured such that one of the contacts coming into contact with each other is actuated by the protrusion of the movable iron core to be separated from the other contact, and the other contact is actuated by the protrusion of the leakage indication button. The earth leakage detecting device according to claim 1, wherein the earth leakage detecting device is configured to be separated from the one contact.